Story: Sea floor geology

Submarine volcanic activity

Submarine volcanic activity

Geologists estimate that three times more volcanic activity occurs under the sea than on land. Around submarine volcanoes there are lava flows, sand and fractured rock. The top photograph is of a fracture – it may be leaking warmer water, as fish seem to be attracted to it. The lower image is of a lava flow. The rounded lumps of solidified rock are called pillow lava, which only form when molten rock – around 1,200ºC – comes into contact with sea water.

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NIWA – National Institute of Water and Atmospheric Research

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How to cite this page:

Keith Lewis, Scott D. Nodder and Lionel Carter, 'Sea floor geology - Active plate boundaries', Te Ara - the Encyclopedia of New Zealand, http://www.TeAra.govt.nz/en/photograph/5622/submarine-volcanic-activity (accessed 27 September 2020)

Story by Keith Lewis, Scott D. Nodder and Lionel Carter, published 12 Jun 2006